6416721 has 24 divisors (see below), whose sum is σ = 9701120. Its totient is φ = 4082400.

The previous prime is 6416689. The next prime is 6416723. The reversal of 6416721 is 1276146.

It is not a de Polignac number, because 6416721 - 2⁵ = 6416689 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (6416723) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 30306 + ... + 30516.

Almost surely, 2^6416721 is an apocalyptic number.

It is an amenable number.

6416721 is a deficient number, since it is larger than the sum of its proper divisors (3284399).

6416721 is a wasteful number, since it uses less digits than its factorization.

6416721 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 357 (or 354 counting only the distinct ones).

The product of its digits is 2016, while the sum is 27.

The square root of 6416721 is about 2533.1247501850. The cubic root of 6416721 is about 185.8251044146.

The spelling of 6416721 in words is "six million, four hundred sixteen thousand, seven hundred twenty-one".